These SKUs are Exhaust Manifolds with Catalytic Converters. The customer communication requested return of unsold inventory due to a loss of CARB certification. These SKUs can no longer be sold as they do not meet CARB standards, but parts on vehicles are not effected.
full bulletin at NHTSA ↗2010 Mercury Mariner engine problems
moderate 18 complaints filed with NHTSA · avg repair $3,100 · see engine across all vehicles →
Failure mileage
Complaints
18
Recalls
0
Avg fix
$3,100
What stands out
Among the 7 model years of Mercury Mariner in our records for engine problems, this one ranks #2 by owner-complaint volume.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
These SKUs are Exhaust Manifolds with Catalytic Converters. The customer communication requested return of unsold inventory due to a loss of CARB certification. These SKUs can no longer be sold as they do not meet CARB standards, but parts on vehicles are not effected.
full bulletin at NHTSA ↗The Powertrain Control/Emissions Diagnosis (PC/ED) manual has been revised for diagnosing electronic throttle bodies (ETBs). The ETC_ACT and ETC_DSD PIDs should not used to diagnose possible ETB concerns. The IDS has a limited refresh rate when reading these PIDs and cannot display quickly enough to validate a concern. The PCM automatically monitors these inputs more accurately and will set diagnostic trouble codes (DTCs) when appropriate. Using these PIDs for diagnostics will lead to inaccurate results and improper ETB replacements. If a concern is intermittent and no DTCs are present, refer to historical DTCs and the PC/ED, Section 3 No DTCs Present Index chart for further information.
full bulletin at NHTSA ↗FORD: DUE TO AN INTERMITTENT LOSS OF RPM OR LACK OF ACCELERATION, IN SOME VEHICLES, WITH ILLUMINATED WRENCH LIGHT, DIAGNOSTIC TROUBLE CODES (DTCS) P2111, P2112 MAY OR MAY NOT BE STORED IN POWERTRAIN CONTROL MODULE (PCM). MODELS 2009-12 ESCAPE, MARINER, FUSION, MILAN.
full bulletin at NHTSA ↗FORD/LINCOLN/MERCURY: SOME VEHICLES MAY EXPERIENCE AN ILLUMINATED MIL OR SAFETY STOP NOW MESSAGE, OR A NO START CONDITION OR POSSIBLE MISFIRE OR ROUGHNESS AT IDLING THROUGH 2000RPM OR A LACK OF ACCELERATION. MODELS 2009-12 ESCAPE, 2009-11 MARINER, MILAN, 2010-12 FUSION, 2011-14 MUSTANGS, 2013 C-MAX, FUSION, MKZ HYBRID.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Fifteen of these eighteen complaints describe sudden, unpredictable loss of engine power—the vehicle drops from highway speed to a crawl or complete stall, often with only a wrench light or check engine light as warning. Owners report this happening at 48,000 to over 140,000 miles, during turns, at intersections, and on interstates. The engine typically recovers after a shutdown and restart, but the problem recurs with increasing frequency.
Dealers consistently struggle to diagnose it when the warning light clears; some cannot find fault codes and charge $59–$100 just to look. When throttle body replacement is diagnosed, costs run $360–$550 and almost never fall under the original 3/35,000 mile warranty or even extended coverage. Ford issued a 2014 recall (13N03) that called for recalibration rather than part replacement—yet owners who had that work done report the failure happened anyway, sometimes years later.
One owner documents a separate A/C desiccant bag failure requiring a $2,700 complete system replacement. Another handful mention check fuel intake or check engine lights paired with cutouts.
No manufacturer recall has addressed the core throttle body problem despite owners citing hundreds of documented online complaints.
Same Mercury Mariner engine reports on nearby years: 2009
Failure modes owners describe
Throttle Body Failure / Loss of Power
Engine suddenly loses power at highway and city speeds, ranging from complete stalls to limp-mode (15 MPH max). Vehicle typically recovers after shutdown and restart. The wrench light (check engine) usually appears during or after the event. This is the dominant complaint across 15 of 18 narratives.
When: Occurs at all speeds and driving conditions; mileage range 48,000 to 142,551 miles. Some owners report incidents within 3-4 years, others much later.
Symptoms owners cite: Sudden loss of engine power at highway speeds (55-60 MPH); Vehicle drops to crawl or limp-mode (~15 MPH max); Engine stalls without warning; Wrench symbol / check engine light appears; Engine runs rough, sputtering, surging; Throttle unresponsive; RPM drops to ~1000; Recovery after engine shutdown and restart
Codes mentioned: Check engine light, Wrench symbol light
Repairs/costs cited: Throttle body replacement: $360–$550. One owner cited $2,700 estimate for full A/C system due to desiccant contamination (separate from throttle). Dealers often cannot replicate the problem or detect codes when wrench light is off; diagnostics can cost $59–$100.
Recalls/TSBs owners mention: Recall 13N03 (2014) offered recalibration instead of replacement; the recalibration did not prevent subsequent failure. Ford claims some failures are outside warranty (3/35,000 miles or extended warranty limits). No broader recall issued despite owner awareness of hundreds of similar complaints.
Desiccant Bag Burst in A/C Accumulator
A single detailed complaint (#2) reports that the desiccant bag inside the A/C accumulator burst, spreading particles throughout the cooling system and clogging components. Owner describes the repair as requiring replacement of all A/C components.
When: Occurred early August 2014; vehicle purchased used in July 2014 with 63,500 miles. A/C worked initially but failed within weeks.
Symptoms owners cite: A/C stops cooling vehicle; Desiccant particles clog A/C system components
Repairs/costs cited: Full A/C system replacement quoted at $2,700. Owner did not proceed with repair due to cost. Dealer advised particles cannot be flushed; complete component replacement necessary.
Recalls/TSBs owners mention: No relief offered by Ford. Owner contacted Ford Customer Relations; dealer suggested NHTSA complaint. Owner notes Google search reveals hundreds or thousands of similar complaints and indicates Ford has been aware for at least a couple of years with no action.
Check Fuel Intake / Check Engine Light with Cutout
Two complaints (#16, #18) mention check engine light and check fuel intake light accompanied by vehicle cutting out or losing power. These may represent the same underlying throttle/fuel control issue or a separate manifestation.
When: Timing not explicitly stated in these narratives.
Symptoms owners cite: Check fuel intake warning light comes on; Check engine light stays on; Vehicle cuts out dangerously at intersections; Wrench light comes on; vehicle limps home; Vehicle loses power; must shut off and re-crank
Codes mentioned: Check engine light, Check fuel intake warning light, Wrench light
Synthesized from 18 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 0 most recent
Had engine trouble with your 2010 Mercury Mariner?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the engine problem on the 2010 Mercury Mariner?
It's a documented issue but not catastrophic. 18 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Across the 17 complaints that reported odometer mileage, most engine failures cluster between 41,179 and 100,000 miles, with the median around 51,000. A quarter of owners report trouble before 41,179; a quarter make it past 100,000. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2010/Mercury/Mariner.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.